Elemental mercury is frequently present in hydrocarbon reservoirs and due to its physical properties and vapor pressure, it is produced in the natural gas phase. Mercury vapor is heavy and the production mechanisms in the reservoir are not completely understood, but some hypotheses mention that it could be produced as puffs or slugs, which could explain the variation between samples.
The presence of mercury in natural gas presents serious health and safety issues. It attacks the central nervous system of humans and accumulates in the liver and kidneys. Mercury can also generate amalgams with common metals; including but not limited to: aluminum, copper, silver and gold. Mercury is under suspicion of causing stress cracking in titanium alloys resulting in catastrophic failure of vessels. Mercury can cause metal embrittlement leading to serious problems in refineries. Therefore, producers, transporters, and distributors of oil and natural gas wish to better monitor the mercury content in such hydrocarbon fluids.